The present invention relates generally to gas separation devices or air filters and particularly to unit type air filters having handles to aid in the installing and removal of the filter in an installation, handles attached to filter device are known.
One example of a filter device having a handle is shown in U.S. Pat. No. 1,676,191 issued to A. Jordahl on July 3, 1928. This patent illustrates a filter having a peripheral frame surrounding a filtering material with a sheet of screen material disposed over both the upstream side and downstream side of the filter to hold the filtering material in place. A pair of handles are attached to the peripheral frame both projecting outwardly of the frame from the same side of the filter.
Another example of a filter device having a handle is shown in U.S. Pat. No. 3,523,409 issued to W. A. Paterson on Aug. 11, 1970. This patent illustrates a filter having a peripheral frame surrounding two layers of spaced apart sheets of filter media. A handle is attached to the peripheral margin of the frame to project outwardly of the peripheral margin so that the filter can be carried in the manner of a suitcase from place to place.
However, the type of handle illustrated in these patents are not suitble for many types of filter construction, and are relatively expensive.
A need exists for a handle construction which is suitable for an inexpensive disposable filter device which is intended to be thrown away when it becomes too contaminated for efficient filtering, and for filters which may not have an exposed frame structure.
Because filters of the throw-away variety are inexpensive, any handle construction must be extremely inexpensive to manufacture and assemble to the filter. Indeed, the cost must be negligible.